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An Appreciation of Dr. Douglas by Dr. ALBERT R. LEDOUX The Bulletins of the American Institute of Mining Engineers and the program of the International Engineering Congress, held last September at San Francisco, called attention to an important feature in the pro¬ceedings of the Congress; viz., the public presentation to Dr. James Douglas of the John Fritz Medal, for notable achievements in mining, metallurgy, education. and industrial welfare. Dr. Douglas' health, unfortunately, did not permit of his taking the journey to California. While he had been willing that the bestowal of the medal should be a public ceremony, his natural modesty made him shrink somewhat from what he considered something of an ordeal, and he begged those who were to take part in it to use restraint in anything which they might have to say as to his work and attainments. It was, therefore, with some considerable satisfaction on his side that he learned that the medal would be given him without a public, ceremony in New York, or elsewhere. . On Dec. 5, 1915, the writer of this had the pleasure of handing him the medal, certificate, and official letters of transmittal, at his home at Spuyten Duyvil, where lie was surrounded by his children and grandchildren, with one or two of his most intimate friends. He begged the writer to return his thanks to the Committee of Award; and again to express the feeling that nothing in his career merited so great an honor. On this point all of the members of the Institute will share the writer's feeling that Dr. Douglas is too modest. James Douglas was born at Quebec, Canada, in November, 1837. His father Was a distinguished physician and surgeon, employing his skill in the field of philanthropy: He established the first retreat for the insane in the Dominion, to which lie. devoted himself up to the time of his departure from Canada, when it was taken over by the Government. The son spent 2 years in study at the University of Edinburgh, which lie entered in 1855. Returning to Canada, he graduated from Queens University, at Kingston, Ontario, with the degree of Bachelor of Arts, having also studied medicine, and later theology. After his graduation he traveled extensively with his father in Europe and in the Orient, visiting Egypt several time's. They returned with important archaelogical collections, which Dr. Douglas subsequently donated to the Metropolitan Museum of Art in this city. He then returned to Edinburgh, where he continued his course in medicine, surgery being perhaps his chief interest at that time. He was subsequently licensed to preach and his contemporaries bore testimony to his broad philanthropy and to the sympathy which dominated his every act. His taste was distinctly literary; he had carried off a prize at Edinburgh in English literature.

Jan 1, 1916

By R. W. Gurry

Thermodynamic calculations indicate that boron is a better deoxidizer than silicon but probably is not quite as effective as aluminum. Boron should, therefore, be readily oxidized out of the open-hearth bath, which implies that it is not recovered in significant concentration from any scrap charged; also that, if added in the ladle, it tends to oxidize out during teeming unless protected by the presence of a better deoxidizing agent. These conclusions do not apply to liquid cast iron, in which the oxygen content is much lower than in liquid steel. The possibility of conserving certain strategic alloying elements widely used in steelmaking, notably manganese, chromium and molybdenum, by the use of boron, which in small concentration appears to be extraordinarily effective in promoting hardenability, raises a question as to what extent any boron present in the scrap charged into the open hearth is oxidized out during melting and subsequent refining. This question is significant because the optimum concentration of boron in the finished steel, which is fairly critical, would be very difficult to attain if the boron in the charge were largely retained in the metal. Moreover, unless boron is substantially eliminated in the open-hearth process its use on a large scale would eventually make it impossible to produce boron-free steel except by restricting the charge to virgin material. There is at present, unfortunately, virtually no satisfactory direct evidence to provide an answer to this question; but there are indications from practice that boron is oxidized out in the open hearth in the production of medium or low-carbon steel, although it may be retained if the carbon content remains fairly high; that is, if the oxygen is kept fairly low. In the absence of direct data, it is necessary to rely upon the indications of indirect evidence, the best approach now available being a thermodynamic calculation of the deoxidizing power of boron in liquid steel by the general method used so successfully by Chipman1 in his study of the reactions in the open-hearth process. The thermal data for boron, upon which such a calculation must be based, are reasonably satisfactory; the only quantities not directly determined are the entropy of melting of boron, the activity coefficient of boron in liquid steel, and the activity coefficient of B2O3in an open-hearth slag; but these values may be estimated with ample accuracy. The results of this calculation, which is presented later, are given in Table I, together with corresponding data for other deoxidizing elements. This table shows the calculated residual content of oxygen in equilibrium with different residual concentrations of the deoxidizer in the metal;

Jan 1, 1944

By C. V. Millikan

Temperature measurement in wells is an old practice and geothermal gradients have been of interest to geologists for many years.le2 Their application to the operation of oil wells is a more recent practice. It has long been recognized that temperature anomalies occur in drilling and producing wells but thermometers that could obtain a satisfactory record of the anomalies were not available. The normal geothermal gradient is con-sidered as being about one degree Fahren-heit for each 60 ft. of depth.4 This "nor-mal " gradient varies in different areas, but whatever it may be in an area there is little variation from the surface to as deep as the : drill penetrates. The normal gradient is appreciably changed by gas expanding ; from the reservoir into the borehole or by the movement of fluid through a borehole : while drilling, producing, or circulating. It is the resulting anomalies and abnormal gradients from which conditions in wells can be interpreted. Some of the applications of such interpretations are locating the position of oil or gas sands, permeable strata in a reservoir zone, gas-oil contact, source of water, casing leaks, and the top of cement behind casing. Thermometers A thermometer for use in wells must be sensitive and have a low thermal lag. The sensitivity should permit recording 0.2OF. or less for differential temperatures although the actual temperature need not be more accurate than 1°F. The thermal lag should be as low as rugged construction will permit in order to allow surveys to be made in a minimum of time. Of the several kinds of thermometers, these requirements are most easily obtained with the vapor-pressure, expansion, and electric-resistance types. Thermometers for use in wells may be self-contained—that is, the complete instrument is lowered into the well and a record made of the temperature—or the thermal element only may be lowered into the well and the temperature recorded at the surface. The vapor-pressure and expansion types are more adaptable for a self-contained instrument while the electric-resistance thermometer is more suitable for surface recording of temperatures. The self-contained instrument can be run against high pressure on a single wire line with only one operator required. The instrument and its hoisting equipment is easily portable and can be mounted on a small car. The disadvantages are a somewhat greater thermal lag and the necessity of completing a run before any temperature or temperature anomaly is known. A surface-recording thermometer has the advantage of being somewhat more sensitive and of having a lower thermal lag. The Operator can see what anomalies are encountered and can immediately change the running conditions of the instrument or the well conditions in order to obtain the most

Jan 1, 1941

By Lester C. Uren

Tars paper reviews the industrial trends and changes in educational concepts that have led to the development of the modern petroleum engineering curriculum. A trend toward emphasis on engineering fundamentals is noted. While most universities are committed to the traditional four-year engineering program, it is agreed that more than four years is necessary for academic preparation of the petroleum engineer in all phases of his profession. The author proposes a coordinated program of undergraduate and graduate training that will permit of adherence to the general pattern of the present four-year engineering course, with provision for extension of the program into specialized graduate courses of professional character. In the latter, emphasis may vary with the interests and objectives of the individual student. A specific undergraduate curriculum is proposed in which upward of 80 per cent of the available time is devoted to engineering fundamentals. A broad survey of the professional field is afforded in courses grouped in the third and fourth undergraduate years, but detailed treatment of the professional aspects of petroleum engineering is reserved for the graduate program. INTRODUCTION Of necessity, engineering curricula must ever be changing to reflect the new techniques, the changing concepts that are presented as the engineering industries develop and unfold. Particularly is this true of the younger engineering curricula representing comparatively new and rapidly changing industries such as the petroleum industry. Institutions that planned their petroleum engineering curricula a decade or two ago now find that the petroleum industry has become vastly more technical in its requirements. En¬tirely new methods and techniques have come into vogue and must be given place in the curriculum, and some of these are of a character that demands changing emphasis in the fundamental preparatory subjects. College and university faculties cannot complacently assume that curricula in this field that were considered appropriate 10 or 20 years ago still reflect the needs of the industry that they are designed to serve. If they do, their graduates will be poorly equipped to meet the requirements imposed upon them by a rapidly changing industry. Perhaps it is not too much to expect academic authorities to anticipate the trends of industry and equip their graduates with what they will need to attain leadership 10 or 20 years after graduation. Whether or not this desirable objective is possible, there is no excuse for allowing curricula to fall behind the current needs of industry. DURATION OF CURRICULUM The majority of our engineering schools and colleges still adhere to the four-year curricula and there appears to be a definite sentiment among many engineers engaged in industry that work should be so planned that the engineering student may secure the essential academic preparation for his profession in a terminal four-year program. Yet, in recent years, it has become increasingly apparent that four years of

Jan 1, 1941

By R. A. Pallanch

Probably one of the most perplexing problems with which a mill operator contends is the proper evaluation of his mill results. True, he accurately determines his recoveries of metals and grades of products monthly, weekly, and often daily. These figures do not of themselves directly translate to mill economics. When one figure is unusually good there may be an offsetting circumstance. The advantage of high lead or zinc concentrate grade may be offset by poorer recovery; high lead recovery may be offset by poorer zinc recovery, or vice versa; and so on. Besides, grades or recoveries may not of themselves mean more than a reflection of the grade and character of the ore during the period under study. What the operator sorely needs is some one measuring stick that tells him when he has achieved his greatest return, regardless of grades or recoveries—for if he knows his methods and practices are yielding the optimum return he need no longer concern himself with the assays of products and tailings, or the corresponding distribution of metal values. At first blush it would appear that the obvious answer to this is the actual money return to the mill. Paradoxical as it may seem, however, money return does not make a dependable yardstick any more than do grades and recoveries, as ore condi- tions would vary enough to bring about greater money return during periods when the actual metallurgical work is not as good. The mill operator, of course, should always aim for the greatest return on the ore, once it is in the mill bins, with proper attention always to mill treatment cost. The need of a proper yardstick becomes more imperative with the increasing complexity of the problem. In the case of a simple, single-product operation on a fairly uniform ore, in which only one metal is of significant importance, the need is not great, as grade and recovery pretty well tell their own story. At the other extreme is the operation that makes three or four separate marketable products from a complex mixture of heterogeneous ores that vary tremendously in individual metal contents and ratios, degree of oxidation, and other characteristics, and in which gold, silver, copper, lead and zinc are all significant values. Economic Recovery The first attempt at obtaining a proper single yardstick for a fairly complex ore with which I am familiar is the use of the ''Economic Recovery" term at the lead-zinc flotation mill of the Sunnyside Mining and Milling Co., Eureka, Colorado. This method had been applied there early in Sunnyside flotation-mill history (not later than 1920) and credit for the innovation I believe belongs to Messrs. Kuryla and Marquand. The term "Economic Re-

Jan 1, 1949

By J. Moore Samuel

THE CHAIRMAN (WALTER DOUGLAS, NEW YORK, N. Y.).-Perhaps there is no problem that causes the modern metallurgist more worry than the question of unaccounted for loss. He has not the advantage of the metallurgist of the early days here, who could sleep peaceably with the settled conviction that there were certain copper mineral constituents of the ore which were volatile, and there was therefore nothing to worry about. The slag contents and volatilization accounted for the balance of the copper that went in the top of the furnace after the weighing of the bullion. There have been great strides in recent years toward reducing this loss. Perhaps the Anaconda company is the one we have to thank for the original pioneer work along the lines which we are all today following. We would be glad to hear from some gentlemen present with reference to their experience with this question of dust losses. E. P. MATHEWSON, Anaconda, Mont.-You mentioned the Anaconda company, Mr. Chairman. I would like to say something about what we have been doing there, and the troubles we have been having. We have a tremendous volume of .gas to handle. We adopted the system of large chambers, lessening the velocity of gases, and incidentally cooling the gases. Unfortunately in one sense and fortunately in another, we were compelled to increase the amount of gas handled in the flue system, and the results were then not so good. Still, we get a very good recovery. Our system of taking a sample is similar to the one described by the writer of the paper. We have tried all kinds of apparatus for getting a fair sample. We divided the area of the flue into imaginary squares, and have taken samples for a certain period of time from each square; and have used the asbestos bags. At present, there is a large unit of the Cottrell apparatus almost ready to connect up on the roaster flue to catch the dust from flotation concentrates. The worst things smelters have to handle at the present clay, they are coming in the Southwest as well as the Northwest, are of material much of which is as small as 500 mesh, and the ordinary methods of catching dust will not apply to flotation concentrates. The Cottrell process is going to be tried out at our plant for this material. We have devised special forms, with a view to preventing the formation of dust from this material, and we are pleased with the results so far obtained. There is another point in connection with this subject that I want to put before the members here, so they will be thinking about it. You know there has been a great deal of litigation between the farmers

Jan 12, 1916

By H. Furman Byars

INTRODUCTION of bottom dump hauling units into the Ray, Ariz., stripping operation of the Isbell Construction Co., was motivated by several reasons, with what appears to be debatable results. The accepted theory of truck design for use in open-pit holds that end dump vehicles are the most adaptable for the work. But, because operations of the bottom dump, under certain construction and haulage conditions, proved economically feasible, the unit was put to work in the Ray copper pit. The decision to try bottom dump was reached after considerable observation of the unit in action on construction of earth filled dams, levees, airport construction and several other similar tasks. Basic tire design also motivated the choice. All things being equal, a vehicle running on low pressure single tires will outperform another operating on dual high pressure tires, providing load carrying capacities are the same. The investment required to equip a vehicle with four single tires to handle the same load as one with dual tires mounted on two axles and single front axles is about 60 pct greater. Thus, in order to reach the break even point on tire costs, single tires must operate 60 pct longer. Comparison is made with a truck outfitted with 10 16:00x25 tires. Two other factors were considered in selecting bottom dump trucks. It was felt the bottom dump principle would work well in dumping ore into a hopper where gate design fits this particular method. Also, with the absence of hydraulic dumping, ore pollution with oil is reduced. The mechanical simplicity of the unit also lent weight to its choice. Ordinary reasoning indicated maintenance costs would be low compared with other units carrying similar loads. The bottom dumping principle is not new. It dates back to the days when horses were used to haul the same kind of rig. The unit employed at Ray holds 25 cu yd struck measure, or approximately 42 short tons. Dumping is accomplished by releasing an air cylinder opening a dog holding the doors. Doors are closed by a cable system operating off a wheel wind deriving power by friction with the trailer tire. The unit is mounted on four 27.00x33 and two 14.00x24 tires on the front axle. The power unit is a 300 hp Cummins engine. Hydraulic power boosts the steering. A straight mechanical drive and friction clutch with 10 speeds is used. Conditions Not Ideal Top performance of the truck can be expected only under the conditions for which it was designed, in particular grades under 5 pct, handling fine material, and dumping where one thin layer can be placed on top of another. The machine will handle 42 tons per haul, operating at high speed, with only seconds used for dumping. On a 2 or 3 pct grade over a one mile haul,

Jan 1, 1952

By Emma Smith, R. W. Guard

INVESTIGATION of the nickel-rich end of the Ni-Zr system has been prompted by an interest in the effect of small amounts of zirconium in high temperature alloys. Hansenl presents a hypothetical diagram based on the work of Allibone and Sykes,2 who investigated the system up to 44 atomic pct (55 wt pct) Zr by metallographic means. Since the alloys they used were melted in Alundum crucibles they were probably contaminated with appreciable amounts of aluminum. They found two compounds which they called Ni3Zr and Ni4Zr. Hayes, Roberson, and Paasche3 identified a compound NiZr (50 atomic pct Zr) with a melting point of 1470°C. Such a high melting compound is not compatible with the observation of Allibone and Sykes2 hat a eutectic is formed near 50 atomic pct. The alloys containing up to 60 atomic pct Zr were melted in an inert atmosphere in a noncon-sumable electrode arc furnace. Analysis of most of the alloys indicated negligible loss of zirconium. The alloys were examined in the as-cast condition and also after annealing for 6 hr at 1175°C (or 1000°C for the alloys between 25 atomic pct and 45 atomic pct). Metallographic specimens were etched using mixtures of HF-HNO3-H2O or acetic acid- HN0,-H,O. The specimens for the solidus determinations were wrapped in molybdenum foil and sealed in evacuated quartz tubes. Specimens to be heated above 1300°C were enclosed in zirconia tubes inside the quartz to prevent reaction with molybdenum. The solidus determinations were carried out by heating the specimens at various temperatures for a few minutes and then examining the interior structure metallographically to determine at what temperature melting began. The 150 mesh powders for X-ray analysis were annealed in an evacuated quartz tube for 2 hr at 540 °C to remove cold work. Alloys with 22.5 atomic pct Zr and 44.4 atomic pct Zr required annealing at 700 °C for complete recovery. The grains of both of these alloys were soft and rather ductile. Both Debye-Scherrer film patterns and spectrometer traces were made for each alloy using filtered copper radiation. Results and Discussion The presence of a substantial amount of second phase in an alloy with 1.1 atomic pct Zr indicated that the solid solubility of zirconium in nickel is somewhat less than 1 atomic pct. The a0 value for the face-centered-cubic matrix in the same alloy was equal to that of pure nickel, so that the solubility must be very small. This observation is as expected from the large atom size difference. Annealed specimens of alloys with 15.0, 16.7, 22.5, 28.6, 44.4, and 59.4 atomic pct Zr showed. micro-structures that were essentially single phase. When

Jan 1, 1958

By K. R. Van Horn

RESIDUAL stresses in metals operate under a cloak of mystery, as they have neither been seen in the laboratory nor detected by means of the microscope. In spite of their phantom-like nature, they frequently exert metallurgical effects that cannot be ignored. In some cases the results have been detrimental, causing rejections or premature failures, but frequently the effects have been highly beneficial to the producer or consumer of metal products. First, however, what is a residual stress? When a metal is plastically deformed by bending, rolling, pressing, or by a phase transformation or precipitation from solid solution, or by a sharp temperature gradient resulting from nonuniform cooling, quenching, or welding, it remains in a state of strain. The strains or strain gradients produced by such operations and retained after all external forces are released are known as residual strains, and the accompanying stresses as internal or residual stresses. Many defects or failures in metal products have been ascribed to residual stresses, sometimes erroneously, because there was no other apparent explanation after the usual metallurgical tools of diagnosis had been applied. For example, during World War 11, the forged aluminum alloy aircraft cylinder head in the reciprocating engine began to replace the cast head with the familiar cooling fins. The fins were machined in the solid forged head by an ingenious milling operation. One plant reported an epidemic of excessive distortion during the delicate high-speed milling. A thorough examination revealed that the composition, heat treatment, mechanical properties, and metallurgical quality of these heads were comparable to those of forgings that machined satisfactorily. It was then claimed that the cause of the machining difficulties was connected with residual stresses resulting from the quenching during the solution heat treatment. An elaborate stress analysis actually demonstrated, however, that the magnitude of residual cooling stresses was lower in the cylinder heads which machined poorly than in those which were satisfactory in this respect. Subsequent tests proved that the machining problems in this case originated from variations in the tools and tool design. Sources of Residual Stresses in Metals Residual stresses are of two origins—mechanical and thermal. Thus, stresses may be produced in a metal by any cold-working process. The distribution and magnitude of these mechanically produced stresses can be calculated in a satisfactory, although approximate, manner for such simple cases as bending, torsion, and expanding of tubes. However, most manufacturing processes are too complex, and the original stress-strain relations in the products are not sufficiently known to permit calculation of the resulting residual stresses. Also, a specific process, such as wire drawing, may vary in complexity or uniformity of working, and large or small residual stresses may result, depending on the conformation of the dies and other features of the working process. Neither substantially unidirectional deformation, such as can be imparted by stretching a metal product having essentially the same mechanical properties throughout the cross section, nor deformation

Jan 1, 1954

With this issue of the Bulletin, the Institute puts into operation a plan which it has long had under consideration for enlarging its field of usefulness to its members. We refer to the Index to periodical literature bearing on mining, metallurgy, and related subjects, which will be found in the advertising section at the end of the Bulletin. The Index is printed on alternate pages so that anyone who desires to compile a card index can readily clip the items and paste them onto cards. By its affiliation with the Engineering Societies Library, the Institute possesses unexcelled facilities for the preparation of this Index, since practically every important engineering or technical paper published anywhere in the world is regularly received by the library. The items for publication in the Index are first selected by the library staff, but their final approval and their order of arrangement remains in the hands of the editor. A word should be said in explanation of the system of classification that has been adopted. It will be noted that the classification is extremely broad, no attempt having been made to gather the references into closely specialized groups. Our reason for breaking away from the modern tendency toward minute specialization is based upon the fact that the fundamental principles underlying all engineering are not by any means so diversified as has commonly been supposed. For example, it is not at, all unlikely that an engineer engaged in large-scale ore mining in the Southwest can profit by observing the methods employed by his colleagues in the Pennsylvania coal mines. It is notorious also how extensively the brotherhood of chemical engineers has profited by the. earlier experiences of the ore-dressing and metallurgical engineers. If the Index were minutely sub-divided, it would always be possible that the coal-mining engineer, for example, might fail to observe a most important paper because it happened to be listed tinder the head of iron mining. For this reason, mining practice in general is consolidated under one head. The same line of reasoning applies to other divisions as well. In order to make the Index of practical value to all members of the Institute, wherever they may be situated, the library will undertake to supply, for a nominal charge, an abstract, a translation, a typewritten copy, a photostat copy, or the original of any article in the Index. Requests for service of this character should be addressed directly to the Engineering Societies Library, 29 West 39th St., New York. Members are urged to cooperate toward the success of this new departure by sending us suggestions. Although every effort has been made to anticipate the wishes of the members, it is almost impossible to foretell what services may be most useful to our 7000 constituents. Furthermore, it is known that some men prefer one method of classification while others would find another method more convenient.

Jan 9, 1918

ROBERT PEELE, * New York, N. Y.-I should like to ask Mr. Neale how the members of the production committees at the individual mines, who came from the mine workers themselves, were chosen or appointed; also from what classes of employees they usually came? J. B. NEALE.-In the union fields, they were chosen by a local. In the non-union fields, they were chosen either by the men in mass meeting or by the company officials. The last way was very unsatisfactory because it gave the men an opportunity to say that they were going to be passed upon as to whether they were slackers or not, by men chosen by the company. When they were chosen by the locals or at mass meetings of the workers, the appointments have been very much more satisfactory. R. D. HALL, ? New York, N. Y.-The matter of inefficiency on the part of the operator is one that I think we may well take into account, because there is a very large inefficiency on the part of the coal operator; it has arisen from reasons almost beyond his control and will continue for these same reasons. It is no use arguing a moral responsibility on the part of the operator, when you make efficiency very largely a loss to the operator who puts it in force. If you ask a man working on a clay wage to work with more efficiency. he says, "Well, I may do it or I may not," it all depends how he feels, but he does not lose anything financially by not working hard. If you ask the man who is working by the ton to put out more tons, he makes a profit by putting out more tons. How is it with the operator? If he gives a man all the cars he needs and all the power he needs, if he runs after his working men and waits on them, he does not get his coal out any cheaper than before.. He gives the man a better chance and there is more efficiency, but at the same time he has increased his expenses all along the line. At the end of the year he finds that his profits have been less than if he had had less efficiency. The efficiency is really against him in many ways. Because he gets a larger tonnage, he reduces the overhead to a certain extent; but hiss tonnage may not be any greater because he may work fewer days. As Mr. Taylor remarked some tine ago, supposing he puts in a machine that is very much more effective than any he had before, he has the same scale; the miner gets out more coal, but he himself does not get any benefit out of it because he has a scale fixed, so much per ton.

Jan 4, 1919

By Marsh S. Watson, Robert A. Howard

An electrolytic model study has been made of the relative productivity of perforated casing. The results show that the relative productivity is roughly one-half to two-thirds of that predicted from point-sink calculations. This discrepancy can he satisfactorily explained on the basis of casing interference. The relative productivity was found to he insensitive to spatial arrangement of the perforations. INTRODUCTION The relative productivity of wells with perforated casing has been treated mathematically by Muskat.' In his treatment the perforations are represented by small spheres, thus enabling him to approximate the flow by that to point sinks. By neglecting interference between the flow into the various spheres representing the perforations, one may deduce the approximate formula Qu 1/rp - 1/rw • (1) I + b/2n _________ 2n In re/rw Where Q is the flow rate into spherical sinks located in the median plane of the sand laver Qo is the open hole flow rate (uncased hole of radius rw) b is the thickness of sand layer under consideration (always one foot in this paper) n is the number of spherical sinks in the sand layer rp is the radius of a spherical sink rw is the well radius re is the drainage radius of the well. Fig. 1 is a comparison of values calculated from equation (1) with Mus-kat's values. It will be observed that the approximate values are in error by less than 21/2 per cent. The disturbing effect of the casing on the flow line; is not explicitly taken into account by Muskat, but he reasons that interference between the flow pat- terns from the various point sinks will result in a negligible flow in the region within the well radius, and that no appreciable error will result from not explicitly excluding flow from this region. This line of reasoning is open to question, however, as the flow impedance, in the immediate vicinity of the well, of a hemispherical cavity in contact with an opening in the casing is twice that of a spherical sink in a continuous sand layer. There will be a difference, moveover, between the flow into a hemispherical cavity and that into a circular hole in the casing. .This latter difference can best be appreciated by comparing the flow from a semi-infinite medium into a hemispherical cavity at the edge of the medium with the flow out of a circular opening of the same radius as the hemisphere and which is also on the edge of the medium. In this case2 ------= —2, showing that the difference in flow rates into differently shaped cavities is quite appreciable. It was the purpose of the investigation reported here to determine to what extent flow into circular perforations in casing departs from the values calculated by Muskat. For this purpose an electrolytic model was used.

Jan 1, 1950

By John Birkinbine

In the belief that a resume of what will be exhibited during this meeting, and a brief record of progress in the seven years which have elapsed since the Institute's first visit to Lake Superior would be interesting, the following statistical data have been prepared or copied from the most reliable sources, and considerations are also presented concerning the development or utilization of some of the resources of the Lake Superior Region. When the Institute, on the return trip from enjoying the charming panoramas of Thunder Cape or Isle Royale, and inspecting the unique development of Silver Islet, passed, in August, 1880, through the St. Mary's Falls ship canal, en route to Escanaba, the boat was lowered from the level of Lake Superior to that of Michigan and Huron lakes (18 feet), through two locks each 70 feet wide and 350 feet long, which had been in use since 1855. But as these locks accommodated vessels which drew 12 feet of water or less, a new lock 80 feet wide, 515 feet long and admitting vessels of 16 feet draught was approaching completion and was opened in September, 1881. The time required to pass the locks was utilized by the members in examining the work upon this new lock and in viewing the Sault Ste. Marie, which in discharging from Lake Superior all average volume of 90,783 cubic feet of water per second, forms a rapid, falling 18 feet in one mile. But the lake traffic through the St. Mary's ship-canal has developed so rapidly that another and larger lock is now required, and work has been commenced by the

Jan 1, 1888

By Earl S. Bardwell

The structural relations existing between cuprous oxide and copper were first systematically studied by Heynl; who suggested that a study of the microstructure of refined copper might be substituted for the analytical methods in vogue for determining the oxygen content of copper coming from the refining furnace. Hofman, Green and Yerxa,2 in their paper A Laboratory Study of the Stages in the Refining of Copper, working along the lines suggested by Heyn, showed that a study of the microstructure could be made to yield a correct estimate of the oxygen content of refined copper. In order to determine the oxygen content of the specimen of refined copper under examination a photomicrograph was first made. From the relative areas of copper and eutectic, the percentage of cuprous oxide and the corresponding percentage of oxygen were then readily calculated. It was found that the values for oxygen thus obtained corresponded closely with the analytical results. With the idea of utilizing this method of determining the oxygen content of each charge dipped from the refining furnaces at the Boston & Montana Reduction Plant, the physical testing laboratory was equipped with suitable apparatus for carrying out the work. It may be of interest to describe certain of the methods which have been worked out in this connection and give such data as have been obtained bearing on the effect of the oxygen content of refined copper upon its conductivity. Apparatus.—For the benefit of those who may be unfamiliar with metallographical apparatus and methods and may be interested to know what equipment is required, a few words with regard to the apparatus are in place at this point.

Jan 1, 1914

As 1970 develops and industrial minerals stand at a crucial point in their progress, research and development programs appear to be the key needed to open up new uses for each mineral's future growth. Radically new processes are needed for making a host of new synthetic products from mineral raw materials which will more nearly meet the demanding specifications required for high performance in space, nuclear and defense applications. Consumer applications for high temperature environments will be needed and are important for continuing the nations economic mineral position. In addition, an acute materials problem limits the effectiveness of some of the newer concepts for controlling ail pollution. What is needed then, according to a report printed by the National Academy of Sciences, is the carefully planned development of a limited number of major centers at universities to provide for both basic research and training of personnel; the nurturing of interdisciplinary mechanisms for research and problem solving within these centers; the achieving of a better balance between physics and chemistry within research, emphasizing the chemical aspects of the material sciences; and the enhancement of a broader professional identity by unifying the various disciplines involved into a possible federation of existing societies which have an interest in the problems. [EE] presents its 1969 annual industrial minerals review, where individual authors evaluate the status of each industrial mineral and recount the major developments which occurred during the year.

Jan 1, 1970

By L. H. Dushak

DURING the war period of quicksilver activity there were a number of departures from what may be termed the classical quicksilver metallurgy. Attempts were made to beneficiate low-grade ores by gravity concentration and flotation; mechanical furnaces began to replace the Scott furnace and the vertical coarse-ore furnaces, and condensers of sewer tile and redwood tanks were used in place of the older brick and stone condensing chambers. Other developments that have occurred during the current period of quicksilver, activity are mainly in the nature of improvement and further refinement of those started during the war period. Each period of quicksilver activity has been accompanied by the proposal of various new processes, including wet methods for the treatment of quicksilver ores and innovations in furnaces, retorts and condenser equipment. As far as the author knows, nothing of economic significance in the way of "new processes" has been developed. There is in fact no real need for any essentially new process for the treatment of quicksilver ores; the direct furnace treatment is simple and inexpensive. Moreover, with fare exceptions, the quicksilver industry has no complex or refractory ore problems corresponding to those which are receiving more and more attention from metallurgists in other branches of the nonferrous field. Under these conditions improvements in quicksilver metallurgy must be looked for through the adaptation of current developments in engineering and metallurgy generally to the particular needs of quicksilver practice rather than through the invention of new processes.

Jan 1, 1930

By Dr. O’Neil Thomas J., Donald W. Gentry

Pure gold was hidden in the quartz, they said, 'Twas proved by dreams and signs, and rods divining, By chemic tests, and spirits of the dead, In fact by everything-except by mining. " from R.E. White, "The Mining Town," Alta California, August 18,1873 Textbooks in mining engineering have traditionally covered ore reserve estimation and mine valuation in a single volume. Indeed, Examination and Valuation of Mineral Property by R. D. Parks (1957), having been the standard of the profession for over 20 years, is a classic example. However, the state of knowledge in these two fields has grown tremendously. Most mining engineering curricula now cover these topics in separate courses, and in practice, these tasks are usually performed by different individuals. Thus, this trend now suggests the need for separate, specialized publications rather than a single volume for both topics. Because of the separate development of the science of ore reserve estimation, it is important to state at the beginning what this chapter does not cover. It does not address in detail the design of sampling programs, sampling methods, or the processing of samples or sample data compilation. There are a number of suitable references available on these topics, including Peters (1978), Gy (1979), as well as the previously cited book by Parks. Furthermore, this chapter does not cover in any substantial detail either the traditional methods for using sample data to calculate ore reserves or the more recently developed geostatistical methods. The traditional methods are thoroughly covered by Popoff (1966) and more concisely by Barnes (1980). Among the more useful references for statistical applications in ore reserve estimation are Barnes (1980), David (1977), and Clark (1979). A thoughtful review of the entire science and art of ore reserve estimation is provided by King, McMahon, and Bujtor (1982). In spite of the fact that expansion of knowledge now calls for separate books on ore reserve estimation and financial evaluation, neither publication can ignore the important interrelationships between the two fields. In regard to this text, the unique and crucial role of ore reserves can not be omitted entirely; however, the field is now simply too extensive to treat here in any comprehensive manner.

Jan 1, 1984

By P. W. Bridgman

IT is characteristic of most scientific investigators that they are not satisfied with the discovery of new facts, no matter how curious or unex-pected, but that along with the factual discovery there is a constant effort to understand. It appears that one's interest in, and satisfaction with, the discovery of an array of new experimental facts is enormously increased if one has at the same time a theory or hypothesis guiding one's expectation of what sort of new experimental discovery may lie around the corner. Conversely, as a theoretical physicist one's satisfaction with his theory is greatly enhanced if along with the development of the theory can go the discovery of new experimental facts, confirming or perhaps modifying the theory as it grows. Of course, there have been long arid stretches in the history of physics in which new data of unquestioned ultimate importance have piled up, without much inspiration or illumina-tion in the way of understanding. For 50 years spectroscopy had such an arid history, but how irksome this was felt to be is plainly shown by the almost audible relief that greeted the first success by Bohr in injecting understanding into the situation, and by the fresh rush of experimenters into this field when the prospect of understanding had once been offered. The investigations in the field of high pressure, which have occupied me for a long time,1 until the last few years have been in very much the same sort of situation as spectroscopy before the advent of Bohr. A great many kinds of data were collected for a great many solid and liquid sub-stances, and there could be no question of the importance of these data, because the uniform change of dimensions produced by hydrostatic pressure is perhaps the simplest conceivable type of alteration to which a body can be subjected. But except for a few isolated flashes, there was no theoretical illumination, so that it had to be to a large extent the enthu-siasm of the collector that kept me going. However, within the last few years the wave-mechanics theory of solids has progressed so rapidly that

Jan 1, 1938

By I. C. White, G. H. Ashley, J. A. Bownocker

Among the rich mineral deposits of the great Appalachian field, the Pittsburgh coal bed stands pre-eminent. Other coal beds may cover a wider area, or extend with greater persistence, but none surpasses the Pittsburgh seam in economic importance and value. It was well named by Rogers, and his able assistants of the First Geological Survey of Pennsylvania, in honor of the city to whose industrial growth and supremacy it has contributed so much. Whether or not the prophetic eye of that able geologist ever comprehended fully the part which this coal bed was to play in the future history of the city that gave it a name we do not know; but certain it is that the 7 ft. of fossil fuel, which, in Rogers' time, circled in a long black band around the hills and, overlooking the site of Pittsburgh from an elevation of 400 ft. above the water of the Allegheny and Monongahela, extended up the latter stream in an unbroken sheet for a distance of 200 miles, has been the most potent factor in that wonderful modern growth that has made the Pittsburgh district the manufacturing center of America, and that bids fair to continue until it shall surpass every other district in the world, even if it does not now hold such primacy.' The Pittsburgh coal bed stands today as probably the largest contributor of wealth of any single mineral deposit in the world. If it is not, what other deposit is? It has contributed to Pennsylvania alone more than 2,500,000,000 tons of high-grade coal worth nearly $4,000,000,000; since 1910, it has added more than $2,500,000,000 to the value of Pennsylvania's mineral output. In 1920, this bed2 contributed 127,227,000 tons of coal as follows: Pennsylvania, Pittsburgh district........................ 38,245,000 Connellsville district................................. 34,095,000 Weatmoreland-Ligonier district........................ 16,107,000 88,447,000 West Virginia, Fairmont district........................ 15,571,000 West Virginia-Ohio, Panhandle No. 8 district............. 21,128,000 Maryland-Potomac (Est. one-third of production)......... 2,081,000 38,780,000 Total........................................... 127,227,000

Jan 1, 1927

By Oswald J. Heinrich

The great improvement which have been made in late years in the different systems and instruments used to perforate the crust of the earth for purposes of testing and exploring for mineral resources or for other reasons, by means of bore-holes of greater or less diameter and to greater or less depths, are manifold. It may therefore be of interest to make an impartial comparison of them, or of such as are most commonly used. Being well aware of the difficulties which are encountered in such a task, a reasonable allowance most be made in such a comparison. It is a rare instance when even two decidedly different systems or instruments have been used in the same locality, penetrating identically the same strata to the same depth. The diameter of a borehole as well as its greater or less depth must also be considered in regard to its cost per foot, etc. But for practical purposes, for exploration at least, we may assert this rule: Any bore-hole, of whatever diameter, which allows the means of examining the strata most carefully and completely, will be sufficient for this purpose, but that one which will do it most economically and in the least space of time, must be considered the best for it. It will, therefore, partially depend upon circumstances, what system, in spite of other superiorities, may be the best in each case, and the following remarks may aid in deciding this question. To make the attempt here to review all that has been published upon the different systems and means of boring would be out of place. Reference can be had to the able publications treating upon this subject. A difference in this respect exists in regard to the use of the hollow rods in connection with the diamond drill, used for that purpose. The great future, which appears to be evident for this instrument, will be warrant enough for any one, who has had the opportunity to test it, to give his experience to the public. Only in this way can we bring this system to such perfection, as it seems to deserve and